How come x-ray's needed to extract a tooth if a major cavity is visible?

Need to see: The roots of the tooth. It helps the surgeon, more information, more likely no surprises.

Information: The dentist needs an xray of the tooth to be extracted to determine the anatomy of the roots. The shape, form, and position of the roots make a difference on how the dentist will approach extracting the tooth. Also the bone levels around the tooth and roots will let the dentist know how to proceed with the extraction. "pulling a tooth" is surgery and we need all the info we can get to plan.